A Review of Three-Dimensional Multispectral Imaging in Plant Phenotyping

Plant phenotype refers to the external characteristics and traits which can be influenced by the interaction between plant genotype and environment, thus reflecting the adaptability and productivity of plants to the environment. As the two critical technical means in plant phenotyping, three-dimensional imaging could provide accurate information about the plant shape, structure, and spatial distribution non-destructively through laser scanning or camera shooting, while multispectral imaging captures plant images in multiple spectral bands to analyze various characteristics of plants. By combining three-dimensional and multispectral imaging, researchers can better understand plant growth and development. In this review, we discussed various techniques and instruments used for three-dimensional multispectral imaging. Specifically, we focused on the instrumentations, their system configuration, and their operational workflows. Furthermore, this survey also explored the key parameters associated with these sophisticated instruments, including spectral bands, computable plant phenotyping parameters, applicable range, and the diverse spectrum of objects they are capable of detecting. In addition, we engaged with the challenges that lie ahead and the promising avenues for future research in the realm of three-dimensional multispectral imaging. This review underscores its remarkable potential in advancing the field of plant phenotyping, thereby revolutionizing crop breeding and management practices.